I find it more straightforward and less error-prone to suggest merge as the default strategy. Team-members who are very comfortable with git can use rebase for a cleaner history. The problems with making rebase the default policy are:

Team members must be mindful of when a rewritten commit history would be problematic. Force-push must be enabled on the remote, and you should be sure nobody is referencing your branch.

When you resolve conflicts during a rebase, you resolve each commit independently, which can be more work than just resolving a single merge commit.